Aircraft Systems

Oxygen SystemsA-4N/TA-4

Aircraft Systems

Oxygen System

LESSON OBJECTIVESTo give the TP information on the Oxygen System to include both the Normal and Emergency Oxygen supply as used in the A-4N and TA-4 aircraft.Introduce the components and location of the On-Board Oxygen System of the A-4N and TA-4

Aircraft Systems

Oxygen System

Describe the location and function of each component of the Emergency Oxygen System.

State the operational pressures of: Emergency Oxygen Cylinder.

State the usage of the Emergency Oxygen

Aircraft SystemsOxygen System

A-4

LOX Quantity Indicator

TA-4

Aircraft SystemsOxygen System

Oxygen Regulator control Panel (A-4N)

Aircraft SystemsOxygen System

NORMAL OXYGEN position - the user will receive a mixture of ambient air and oxygen up to FL 340?

100 PERCENT OXYGEN position - 100 percent oxygen will be provided at any altitude.

RED EMERGENCY TOGGLE - Located on the left side of the regulator, provides a means of manually supplying positive pressure for testing mask fit and for emergency use.

• Directs a steady stream of 100 percent oxygen to the mask, making it operate as a continuous flow system regardless of altitude.• Use with suspected hypoxia, unconsciousness or serious leakage in the mask or delivery hose. • Use of the emergency setting, however, depletes the oxygen supply in a relatively short time and causes difficulty exhaling when wearing the face mask.

Aircraft Systems

Oxygen System

A-4N

Before Flight (engine running and normal power on aircraft)Prior to each flight, the oxygen system and mask shall be checked for

proper operation.

1. Connect the oxygen supply hose and tube2. Observe and check the white blinker on normal and 100% Oxygen

setting. 3. Select Test and check for positive pressure flow

Note

If exhalation is difficult, there is inhalation valve leakage

Aircraft Systems

Oxygen System

In the TA-4 the Oxygen control is commanded from the aircrew services panel located on the left aft console. It is a simple ON OFF toggle to control flow.

Aircraft Systems

Oxygen System

Before Flight (engine running and normal power on aircraft)

TA-41. Prior to each flight, the oxygen system and mask shall be checked for

proper operation.2. Connect the oxygen supply tube to the connector on the survival kit

with the mask turned away from the face. Place the oxygen switch in ON. Listen for free flow of oxygen. Put on the mask. Inhalation should be almost effortless if the regulator is delivering oxygen at a slight positive pressure. Exhalation should also be possible but will require some effort in order to close the inhalation valve.

NoteIf exhalation is difficult, there is inhalation valve leakage

Aircraft Systems

Oxygen System

Oxygen Duration

Aircraft Systems

Oxygen System

EMERGENCY OXYGEN SYSTEM

The emergency oxygen system supplies oxygen to the pilot automatically during seat ejection. Provides a supplemental quantity of oxygen for in-flight usage when the pilot pulls the green ring on the left-hand side of the seat pan cutout. Oxygen flows from the bottle for 4 to 20 minutes or longer, depending upon the altitude at the time the release mechanism is actuated.The principal components of the emergency oxygen system are as follows:1. Emergency oxygen bottle2. Pressure reducer valve3. Emergency oxygen bottle check valve.4. Filler valve5. Oxygen hose.

Aircraft Systems

Oxygen System

RSSK SEAT PAN

Emergency Oxygen System is contained within the RSSK seat pan/survival kit.

Aircraft Systems

Oxygen System

PRESSURE REDUCER VALVE Actuation of the pressure reducer valve is accomplished automatically (from the emergency lanyard) or manually by

pullling the green ring. – Releases the emergency oxygen at a pressure of 50±10 psi The integral relief valve will operate to vent the oxygen supply if the orifice fails to reduce the pressure below 125 ±5 psi.integral relief valve will not permit release of the emergency oxygen supply unless the output pressure of the OBOGS oxygen system is below 50±10 psi

Aircraft Systems

Oxygen System

CHECK & FILLER VALVES

The emergency oxygen bottle CHECK VALVE prevents oxygen in the emergency oxygen bottle from entering the OBOGS oxygen system before ejection, or from escaping to the atmosphere after ejection.The FILLER VALVE provides a means for replenishing the gaseous oxygen supply in the bottle.

Aircraft Systems

Oxygen System

NORMAL PROCEDURES

EMERGENCY OXYGEN PREFLIGHT Prior to flight, the following inspection of emergency oxygen should be made:1. Check pressure gage for adequate supply (1800psi) gauge in green region.2. Check that emergency oxygen actuator lanyard located on cockpit floor is attached to the aircraft.3. With the mask-to-survival kit hoses connected and the Aircrew Service Panel flow switch “OFF”, check that there is no oxygen flow.

(TA-4 REGULATOR MASK)

1. Oxygen quantity—CHECK

If able to descend:

2. Cabin altitude to less than 10,000 ft

If unable to descend:

3. Green O-ring on seat—PULL

4. Oxygen supply lever—OFF

5. Connections—CHECK SECURITY

6. Land as soon as conditions permit

OXYGEN EMERGENCY OPERATIONS

Aircraft SystemsOxygen System

1N

1N Once emergency oxygen is actuated oxygen flows until the emergency bottle is depleted (approximately 4 to 20 minutes).

Aircraft Systems

Oxygen System

(A-4 DILUTER REGULATOR)

1. Supply lever—ON

2. Diluter lever—100% OXYGEN

3. Emergency lever—EMERGENCY

If no positive pressure or suspect oxygen

Contamination and unable to descend:

4. Green O-ring on seat—PULL

5. Oxygen supply lever—OFF

6. Connections—CHECK SECURITY

7. Breathe at a rate and depth slightly less than normal until symptoms disappear.

8. Cabin altitude—DESCEND BELOW 10,000 FT

9. Land as soon as conditions permit

1N

Once emergency oxygen is actuated oxygen flows until the emergency bottle is depleted (approximately 4 to 20 minutes).

1N

Oxygen supply is rapidly reduced when either or both crew members demand 100% oxygen or when the emergency lever is held in the EMERGENCY position.

2W

2W

OXYGEN EMERGENCY OPERATIONS